Patch systems vulnerable to critical Log4j flaws, UK and US officials warn

CVE-2021-44228 is one of the most severe vulnerabilities to come to light in the past few years. It resides in Log4J, a system-logging code library used in thousands if not millions of third-party applications and websites. That means there is a huge base of vulnerable systems. Additionally, the vulnerability is extremely easy to exploit and allows attackers to install Web shells, which provide a command window for executing highly privileged commands on hacked servers.

The remote-code execution flaw in Log4J came to light in December after exploit code was released before a patch was available. Malicious hackers quickly began actively exploiting CVE-2021-44228 to compromise sensitive systems.